Smart cards using an integrated circuit (IC) chip or a combination of an IC chip and a magnetic strip are classified into contact types and contactless types. Contactless smart cards can employ radio-frequency (RF) communication or near-field communication (NFC) to communicate with a compatible reader and have been used as credit cards, transportation passes, identification cards, membership cards, and the like.
While such cards are generally made substantially of plastic materials such as polyvinyl chloride (PVC), card-issuing companies have found a need to produce metal smart cards, which can feel and look more sophisticated and higher in quality. Accordingly, metal smart cards have grown in popularity in recent years; for example, credit card companies may issue metal credit cards to customers with high credit ratings or high net worth.
However, such metal smart cards have been by and large limited to contact-type smart cards. When metal layers are incorporated into contactless type smart cards, the attenuation of any kind of RF or NFC signal due to the presence of the metal layers often makes contactless metal cards unusable.
To overcome this problem, plastic contactless cards having thin metal film layers have been used. However, such films are susceptible to deterioration or discoloration. Additionally, a plastic card having a metal thin film lacks the desirable heft of a card having substantial metal layers.
The introduction of a slit through a part of a metal sheet has been proposed to allow metallic layers to have contactless communication capabilities (for example through a metallic case of a smart phone). However, when incorporated into flat cards, the incorporation of a slit is detrimental to its structural properties. Namely, a card having a slit can be highly susceptible to cracking and breaking. Such fragility is not desirable in smart cards that are frequently handled and may be subject to flexing, dropping, or other abuse. For example, a credit card having a slit may be put into a wallet and subsequently be sat on resulting in the card breaking due to torsional and normal stresses.
Therefore, there is a need for a metal contactless smart card that is durable. This invention is directed to address the above problems and satisfy a long-felt need.